Integrating Explanation and Evidence in Belief Revision

Adolescents from two samples (n=109) freely investigated a multivariable database to ascertain the extent to which their initial beliefs were affirmed or warranted revision. The study’s purpose was (a) to examine the strategies used, and (b) to identify the respective roles of explanation and evidence in the process. Participants were randomly assigned to one of three conditions. In Condition 1, explanations were solicited prior to and following data investigation. In Condition 2, explanations were solicited only following data investigation, and in Condition 3, no explanations were solicited. Consistent across age groups were the ways in which explanation influenced beliefs and benefitted belief revision. Only 8% in sample 1 and 10% in sample 2 applied the investigatory strategy of controlled comparison (COV) that is a staple of the middle-school science curriculum. Instead, they mostly used a less reliable strategy of examining the data broadly to identify favorable outcomes and then implicating antecedents often co-occurring with them. Accurate belief revision nonetheless occurred, slightly more successfully among the young adolescent sample, who made more frequent reference to the data in justifying their conclusions. Yet, consistent across both age groups were the ways in which explanation influenced beliefs and benefitted belief revision. Explanation facilitated belief revision in both conditions (1 and 2) in which they were solicited, underscoring the need to consider both explanation and evidence investigation in examining belief revision.